West Bengal's best-known expert on rivers, Kalyan Rudra, 62, and Babu Bhai, a 32-year-old fisherman, have a common lament-hilsa, the fish that can tingle Bengali taste buds like nothing else on earth, has gone missing from the Ganga. The fisherman, who's plied his little boat from the rusty jetty at Kolkata's Bagbazar for nearly two decades, is worried because he can no longer make ends meet with the scant catch he nets these days. Even the swelling monsoonal tides this July failed to bring in the fish. The scientist, disappointed like every other Kolkata resident at having to forego his favourite delicacy, however says that the hard-to-find-herring could be a forewarning of something far more ominous, even catastrophic.

Incessant influx of noxious pollutants from riverbank industries and sewage alongside enhanced rates of siltation and saline water incursions from the Bay of Bengal since the barrage at Farakka was completed in 1975, may have distorted the natural dynamic equilibrium of the river but has, more significantly, permanently altered the Ganga's biodiversity. Like the sought-after fish, he also points to the absence of the endangered Gangetic dolphin.

This is what three Union ministers-Uma Bharti, Nitin Gadkari and Shripad Yesso Naik-handpicked by Prime Minister Narendra Modi, set out to change in the Capital on July 7 at 'Ganga Manthan', a brainstorming with various stakeholders to resurrect India's greatest river to its former glory.

West Bengal hilsa at a local fish market in Dum Dum, Kolkata.

On the cards are plans to build a string of tourism hubs and the excavation of a 45-metre wide and 5-metre deep navigation channel all the way from Varanasi to Kolkata. Road Transport and Shipping Minister Gadkari is hoping that the World Bank will foot a big chunk of the yet undetermined cost. The ministers also spoke of building barrages at 100 km intervals. To back this up, Finance Minister Arun Jaitley allocated Rs 2,037 crore for Ganga rejuvenation including Rs 100 crore for developing riverbank ghats, as part of his budget proposals on July 10.

The Ganga in West Bengal, often referred to as the Bhagirathi and the Hooghly further south, is fuller with water than at Kanpur or Varanasi. But even the fresh inflow from Farakka fails to rescue the river along its 500 km course from Jalangi in Murshidabad district to the sea. Upstream in Bihar, besides the sullying of the river with municipal and industrial waste, unmindful, unregulated sand mining and widespread encroachment of the Ganga bed threatens its existence.

Oh! Calcutta!

"Polythene toh amar hai. kabhi khatam nahi hota (Polythene is indestructible)." This is a wisdom that Babu the fisherman learns each time he goes out in his boat. Something of a legend amid fellow boatmen since he netted 2-3 kilo hilsas successively over several days, but that was more than a decade ago. "Now all I ever catch is plastic bags," he grins despite the diminishing prospect of a livelihood from fishing. His catch over a week in early July comprised barely 600 grams of sardine-like specimens that nobody was willing to buy. Babu confesses he is seriously contemplating a change of vocation.

Upstream in Malpara, another fisherman, Sujoy Haldar, 36, who is now a part-time construction worker, confirms, "there is no hilsa in the Ganga this year". Though he has had better luck than Babu with minor quantities of less-in-demand fish like chingri, bhetki, bacha and bele, Haldar says it doesn't earn him enough to feed his family of four. "I have a daughter in school and old mother who needs regular medicine," he explains.

The fishermen blame a multiplicity of factors for their current troubles. "The Ganga is much too polluted," says Haldar. According to him, the hilsa, which is essentially a marine fish that, like the salmon, swims upstream into the river to spawn ahead of each monsoon, has begun avoiding the Ganga both because of its huge load of pollution as well as the fact that the river channel has become shallower with silt.

A former chief engineer of the Kolkata Metropolitan Development Authority (KMDA) who was associ-ated with both phases of the Ganga Action Plan (GAP 1 & 2), Sujit Kumar Bhattacharya, 68, admits that there are some 326 drains that continue to dump stupendous volumes of raw, untreated sewage into the Ganga.

With a densely located population of 14.1 million as per the 2011 Census, the Kolkata Metropolitan Area, comprising three corporations, 38 municipalities and 527 smaller towns and villages, was disposing an unbelievable 1,350 MLD (million litres per day) of sewage into the river at last count in the late 1990s. Bhattacharya agrees the volume could only have gone up in the past decade-and-a-half with growing population and that 19 sewage treatment plants set up under GAP 1 are functioning at less than 20 per cent capacity.

But wait, there's more: Kalyan Rudra, who has worked as member of the Fluvial Geomorphology Group of the IIT expert committee set up by the government under the National Ganga River Basin Authority (NGRBA), says there is scant supervision of the effluents belched out by over 150 large industrial units located along the Ganga bank in Kolkata. "These plants contribute nearly 30 per cent of the contaminants entering the river," he says.

The filth stares you in the face no more than a stone's throw away from Chief Minister Mamata Banerjee's residence in Kalighat. Tolly's Nullah, once a source of fresh monsoonal run-off during the British Raj, is now a reeking sewer. It is a dense, slow-moving sludge that ceaselessly flows into the muddy waters of the Ganga.

The theme hardly varies at any of the 326 sewage inflow points. The Howrah Drainage Canal, which carries in waste water from the densely peopled corporation area of the city, would be mistaken for a major river in Europe. Only, it carries a oily, black and sulphuric mix that flows well into the Ganga before it merges. A group of young boys from nearby Nazirganj have devised a game: The challenge is to dunk oneself in the black sludge and then swim out to wash it away in relatively 'cleaner' water further midstream. "It's great fun," says Man Bahadur, a 15-year-old Nepali migrant clearly ignorant of the dangers that lurk in the poison.

Sixty-year-old Zainum Khatoon toils at picking bits of metal from a heap of foundry ash at a small aluminum-recovery unit on the riverbank adjacent to the mostly abandoned Sagardutta Ghat in North Kolkata. Working next to the mouth of another big sewer, the workers are not overly concerned over our intrusion: "No one ever comes here. You are the first outsiders in years to show up,"Khatoon says, unaware that what she does for a living only adds to the poison in the Ganga.

While almost nothing of significance has been attempted to rescue the river from continuous pollution, Chief Minister Banerjee's Hooghly Riverfront Beautification project-a multi-crore-rupee cosmetic exercise launched in 2011 and most likely inspired by then Gujarat chief minister Narendra Modi's success with the Sabarmati waterfront in Ahmedabad-promises to metamorphose Kolkata-on-the-Ganga.

Well into the first phase of implementation, the project has, however, riled activists who want real change. Subhas Datta, 64, a chartered accountant-turned Clean Ganga campaigner who has filed nearly 70 public interest petitions before the Green Bench of the Kolkata High Court since 1995, says, "Making the bank look pretty while muck flows beneath is like using lipstick to mask a smelly mouth."

Kalyan Rudra is, however, slightly more indulgent and acknowledges the politicians' need to seek development that is tangible and can be seen by their constituents. "Water quality is not always tangible," he says.

Patna's short shrift

The Ganga enters Bihar near Buxar and is fed by tributaries Ghaghra, Gandak, Son, Bagmati and Kosi on its 445-km course-18 per cent of its total length-through the state. Though Ganga water isn't used in Bihar for large-scale irrigation due to restrictions imposed by the 1996 Farakka water-sharing treaty between India and Bangladesh, the entire stretch of the river in the state is choked by rampant illegal sand mining and ill-planned urbanisation. The lucrative trade, fuelled by construction boom, has also led to turf wars between gangs in the sand-rich areas of Lakhisarai, Saran, Bhojpur, Nawada and Patna districts which has claimed nearly a hundred lives. "Unregulated and excessive removal of sand has caused soil erosion, riverbed coarsening and channel instability, in addition to degradation of riparian and aquatic species," says R.K. Sinha, head of Patna University's zoology department and a member of NGRBA.

The Ganga riverbank has also seen a mushrooming of brick kilns-6,000-plus according to the official count and thousands more illegally. The brick kiln waste, which is dumped directly into the river, diverts the flow and direction besides polluting the river water. A 2013 NGRBA report states that 671.4 MLD of waste water goes into the Ganga untreated every day in Bihar. Though there are seven sewage treatment plants in the state, the faecal coliform count in the stretch of the Ganga in Bihar is much higher than the permissible limit of 500 MPN (Most Probable Number) per 100 ml.

A river has a lateral-shifting cycle of around 70 years. But brick kilns operators in Patna have forced the Ganga to shift its course northward during the last 25 years and cede land-a scarce resource in a city of over 5.8 million with a density of 1,823 people per sq km. The shift away from the bank in Patna is as high as 5-8 km. The first victims of the river shift have been residents of riverine lands like Nakata Diara, which a shifting Ganges has cut through and engulfed. The urban population in Patna has also felt the pain-almost all ghats in the city where Chhath festivities were earlier observed have dried up.

There was a time when Patna's waterfront was more than 20 km. Now, at least 70 per cent of it has been lost due to land encroachment beyond the Ganga protection bund, a linear cemented wall constructed on the northern fringes of the city in the 80s to prevent flood waters from entering. "The river can surely flood the dried-up riverbed," warns Sinha, adding that the riverbed and floodplain must be demarcated to save the Ganga-and ourselves for its unpredictable fury.

The Modi Government's new proposals to make corrections along the 2,525 km course of the Ganga, albeit preliminary, are raising serious questions among experts. Kalyan Rudra, who stayed away from the 'Ganga Manthan' in Delhi, is particularly confounded with Nitin Gadkari's notions about dredging a navigation channel all the way from Varanasi to Kolkata: "The river will not allow it," he says predicting that to maintain its dynamic equilibrium, the Ganga would rapidly re-silt and fill up any such artificial waterway.